FIELD OF THE INVENTION
This invention relates to a method of injection moulding a pallet comprising a reinforcing frame provided with an encapsulation of thermoplastic polymeric material.
In the moulding of pallets large horizontal injection moulding machines may be used and, since the reinforcing frame extends over substantially the whole area of the faces of the pallet, the frame has to be held against considerable forces during injection. In a horizontal injection moulding machine the platens which carry the mould parts move towards and away from one another in horizontal directions between open and closed positions.
When injection moulding a reinforced pallet in such a machine it is necessary to hold the reinforcing frame against movement in the mould cavity at least during the initial stages of moulding. It is preferred to hold the frame with projections which extend horizontally and which prevent movement of the frame during moulding. On the other hand, since the frame has to be held in or on one of the mould parts before the mould is closed, the horizontal projections which are desirable for holding the frame in the cavity during moulding cannot be used to hold the frame initially before the mould is closed.